Pineal Gland Study. Dr. Marquez hypothesized that fluoride had a deleterious effect on the pineal gland, which helps with sleeping. He measured the amount of fluoride in Americans and compared it to the fluoride level in Europeans, where its use in drinking water has been banned. He knew from reading the literature that the average fluoride level in Europeans was 40 parts per million (ppm). He collected a representative sample of 625 Americans and found that their fluoride level was 60 ppm with a standard deviation of 250 ppm. What is the value of the z-test statistic?

In a study conducted at Virginia Tech, the plasma ascorbic acid levels of pregnant women were compared for smokers versus nonsmokers. Thirty women in the last three months of pregnancy, free of major health disorders and ranging in age from 15 to 32 years, were selected for the study. Prior to the collection of 20 ml of blood, the participants were told to avoid breakfast, forgo their vitamin supplements, and avoid foods high in ascorbic acid content. From the blood samples, the accompanying plasma ascorbic acid values were determined, in milligrams per 100 milliliters. Is there sufficient evidence to conclude that there is a difference between plasma ascorbic acid levels of smokers and nonsmokers? Assume that the two sets of data came from normal populations with unequal variances. Use a P-value. Click the icon to view the plasma ascorbic acid values. Let sample 1 be the nonsmokers and let sample 2 be the smokers. State the null and alternative hypotheses. Hoi Hi-H2 = 0 (Type integers…

oli.cmu.edu/course/a2/rest/assessement/deliver?attempt=1&context=7e118d530a0001dc243d5eafc726f6eb Countdown: Days:-0 Time:-12:02:41 10 points Researchers created a new fertilizer. They conducted an experiment to compare the new fertilizer to the old fertilizer. They divided tomato plants into two groups. They applied the new fertilizer to one group and the old fertilizer to another group. The variable is the number of tomatoes per plant on a randomly selected day. 0 0 Old Fertilizer N=65 2 4 New Fertilizer N=58 4 6 6 20 600 8 8 10 10 12 14 16 12 14 Number of tomatoes per plant 18 16 18 20 20 Select one answer. Which one of the following statements is valid? A. O The new formula of fertilizer works better. Plants with the new fertilizer had more tomatoes. B. O The old formula of fertilizer was better because the plant with the most tomatoes was treated with the old fertilizer. The average number of tomatoes per plant with the old fertilizer is higher than the average amount of tomatoes…

Question 20